So after a successful install of Arch I installed the vesa video driver and then Xorg. I worked through the Xorg page on the Arch wiki and it seems to be configured properly, but when I "startx" into xterm or lxde or whatever, the screen resolution has failed to set itself to what I put in my 10-monitor.conf. Instead the resolution is tiny and the picture resides within a black border around my screen. I have never encountered this problem in any other Linux distribution.

My card is an ATI Radeon HD 4870; my display's max resolution is 1920x1080. In addition to the vesa driver, I have tried the open source ati and radeonhd drivers with no success. What is different about Arch Linux that causes my hardware to not be detected properly?

Hello hajatvrc,

I'm a newbie with Arch as well. I also experienced a low resolution at first after installing the x-server.
Yesterday I found this: http://wiki.archlinux.org/index.php/ATI
I've a Radeon HD 3470 and after installing the xf86-video-ati package and some changes in the configuration it works very well vor me.
You may use the arch-wiki page like a cookbook.

Markus